Yes, but for exemple
On betfair, you can choose your odds.
So for exemple, I can choose for exemple in "your odds" 3 (for Tipsa to win) and put 2$ (it mean that my profit will be 4$) and I choose in "your odds" 5 (for Youzhny to win) and put 2 $ which means that if he wins, I will win 8 $.
Even though I lose my other bet, I always win something (and a lot)
Just because you can 'choose' your odds doesnt mean that somebody else will 'choose' to take your bet.